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Патент USA US3084135

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Apr1l2, 1963
F. J. SODERQUIST ETAL
3,084,125
METHOD OF DEHYDROGENATING ETHYLBENZENE TO
STYRENE AND A CATALYST THEREFOR
Filed Dec. 22, 1958
DEHVOROGENA TlO/V OF ETHYL BENZENE
/0. 000
(0 OQO
8.000
Ga/sS’z134cf0g/ur5be.n,
7.000
'
6.000 ’
/
5.000
4 .000
/Pe9rc/en6 Fern?
8
/
/
2
3
4
5
6
Percen/ vanadium /'/1 00/04/01‘
INVENTORS.
Freo'en'ck J Soa'erqun'sf
A 00/0
Freve/
Haro/ 0. d?ogz/ce
51/ 4409619.
ATTORNEY
3,084,125
United States Patent 0 ” ICC
Patented Apr. 2, 1963
1
2
3,084,125
catalyst ingredients are dry blended to give an intimate
dispersion and thereafter su?icient water is added to pro
- ZENE T0 STYRENE AND A CATALYST THERE
vide a slurry or paste which can be extruded. The slurry
Frederick J. Soderquist, Essexville, Ludo K. Frevel, Mid
land, aud Harold D. Royce, Coleman, Mich., assignors
pellets of the desired size, advantageously ~71‘; in. in diame
to The Dow Chemical Company, Midland, Micin, a
corporation of Delaware
Filed Dec. 22, 1958, Ser. No. 782,063
about 16 to 20 hours, and then are oven dried at a tem
METHOD OF DEHYDRGGENATING ETHYLBEN
or paste is then extruded and chopped to give catalyst
FOR
ter. The pellets are then air-dried, advantageously for
perature of about 110° to 150° C., advantageously for
about 16 to 20 hours. The catalyst is activated prior to
10 use by heating it at a temperature between about 200°
1 Claim. (Cl. 252—430)
and about 650° C. in a current of steam for several hours.
This invention concerns a method for dehydrogenating
ethylbenzene to styrene and a novel catalyst useful there
for.
Advantageously the catalyst is heated up to about 400°
C. and thereafter is heated up to about 650° C. for about
-
i 4 hours in a current of steam.
The use of the so-called self-reactivating catalysts for
Dehydrogenation of ethylbenzene to styrene is accom
15
the dehydrogenation of alkylbenzenes has been Well
plished by passing a mixture of ethylbenzene and steam,
publicized in various patents and technical articles, par
advantageously about 2 weight parts of steam per part of
ticularly by K. K. Kearby. These catalysts usually com
prise major quantities of Fe2O3, ZnO, or MgO, with
ethylbenzene, over the catalyst at a space velocity and at
Similarly, the literature ,has many references to the use
of vanadium salts in conjunction with activated alumina
ranging between about 550° and about 675° C. and a
space velocity of about 0.5 gram of ethylbenzene per ml.
a temperature sufficient to maintain conversion at about
minor quantities of chromium and/or copper salts, and
always include a basic compound of the type K20 or 20 20 to 50 percent, preferably about 40 percent. Such a
conversion is advantageously achieved with a temperature
K2CO3.
-
or other acidic type materials for dehydrogenation re
actions.
25
‘It has been considered impractical to combine these
two catalyst types in one composite material because of
the effect the acidic components have on the K20 or
K2CO3. _ (See Ind. & Eng. Chem. 42: 298-300, 1950.)
gases are analyzed by mass spectrometry.
The following examples illustrate speci?c embodiments
of this, invention.
'
EXAMPLE 1
It has now been discovered in accordance with this in 30
vention that nominal amounts of a vanadium oxide source
of catalyst per hour. Product samples are analyzed by
vapor phase chromatography. Non-condensible vent
The following rcatalystmixture was prepared, the pro
portions of ingredients being given as weight percentages.
material, i.e., an oxide, salt or other compound thermally
Fe2O3 _
decomposable to an oxide, such as a vanadium oxide,
ZnO _
sulfate, oxysulfate, sul?de, or a vanadate, in amounts up
to 2.5 Weight percent calculated as elemental vanadium, 35 C1120
total catalyst basis, not only may be added to the basic
catalysts without destroying their self-reactivating proper
_
_
29.7
29.7
._
8.9
, K2CO3
8.9
Lumnite cement ____________________________ __ 3.9
ties and catalytic e?iciency, but also such nominal addi
Graphite
5.1
tions result in catalysts superior in efficiency to the same
Methocel
4.0
40
material without vanadium. None of these compounds
is poisonous of the basic type, self-reactivating catalysts
V205
of this invention, i.e., none contains a harmful negative ”
___
__
100.0
ion such as bromide, oxybromide, chloride, oxychloride,
silicide or a free acid component capable of forming a
The mixture was dry blended in a Lancaster Blender
potassium salt with an alkali metal carbonate or oxide, 45 for approximately twenty minutes until intimate disper
e.g., a vanadic acid.
Furthermore such improvement
can be accomplished only by limiting the quantity of the
sion of the ingredients was obtained. Blending was con
tinued for another ?fteen to twenty minutes, during which
vanadium added to 2.5 Weight percent or less, and pref
erably less than one’ percent and by incorporating the
vanadium compound in the initial dry or wet blended
time 140 grams of distilled water was slowly added until
a slurry or paste suitable for extrusion was obtained.
Thevwetted materials were then transferred to a California
extrusion mixture prior to the catalyst fabrication.
Laboratory Model Pelleting Mill and extruded as rapidly
as possible through a ‘@716 inch rotary die and chopped to
form 3/16 inch diameter pellets. The pellets were collected
The catalysts of this invention are prepared by mixing 7‘
a ‘major amount, i.e. in excess of 50 weight percent of
one or more of the oxides Fe2O3, ZnO and MgO with a
minor amount less than 10 weightrpercent of an alkali 55
metal chromate or dichromate, an alkali metal carbonate
or oxide, and up to 2.5 weight percent calculated as
vanadium of a vanadium oxide or a vanadium compound
or salt which yields a vanadium oxide at elevated tem
peratures Whose anions have no harmful effect on the 60
catalyst.
To these essential catalyst ingredients, it is
preferred to add a minor amount less than 10 weight
percent, of porosity promoting and extruding aids such
as graphite and a methyl cellulose whose 2 percent aque
on trays and air dried at room temperature for sixteen to
twenty hours. They were then transferred to an oven and
dried at 110° to 150° C. for an additional'sixteen to
twenty hours.
After drying, a 70 ml. sample of the pellets was placed
in a vertical, electrically heated reactor tube with suitable
feed, vaporizing and recovery appurtenances. The
catalyst temperature was immediately raised to-200° C.
and held there for two hours, raised rapidly to 300° C.
and held for two hours, the steam' flow'started (161.2
g./hr.) and the temperature raised to 400°C. and held
ous solution at room temperature has a viscosity from 65 for two hours, raised to 600° C. and held for two hours,
2000 to 3000 centipoises a stabilizing oxide such as Cu2O
and a refractory cement resistant to elevated tempera
tures and to steam, for example lumnite cement. The
then ?nally raised rapidly to 650° C. and the ethylbenzene
flow started (31.0 g./hr.). Thereafterthe temperature
was adjusted so that approximately 41 percent styrene.
3,084,125
3
4
was produced in the crude product. The operation was
continued for a total of 458 hours from the time the
hydrocarbon ?ow was started. During this period of
Run *1 was made using a standard self-reactivating
catalyst with no vanadium addition. The balance of the
runs were made with vanadium-containing catalysts, the
time eight liquid composite samples of the product were
quantities and particular vanadium compound employed
completely analyzed, and in addition two gaseous samples C21 being shown in the table.
of the non-condensible vent gases were taken and
The mode of operation was to adjust the temperature,
analyzed.
keeping the ?ow rate constant, until approximately 41
Table I presents a summation of the data from depercent conversion was obtained, thereafter changing only
hydrogenating ethylbenzene over such catalysts. Each
the temperature so as to keep this conversion level con
horizontal tabulation represents some 300 to 400 hours of 10 stant. The vanadium-containing catalysts’ superiority is
continuous operation during which time six to eight comapparent not only in the higher ultimate yields shown,
posite product samples were taken and analyzed, the
but also in the lesser quantities of vent gases produced.
values shown being the average of these determinations.
The vent gas directly re?ects the thermal degradation or
The gasi?cation was measured using a water displacement
degree of secondary reaction that the processed material
meter at room temperature and pressure. Vapor phase 15 undergoes when conversion levels to styrene are held
chromatography was used for the analysis of the liquid
constant.
Table l
SELF-REAGTIVATING STYRENE CATALYSTS
Catalyst composition, weight percent
Bun No.
F0203
Z110
30.0
29.5
28. 9
29. 7
C1110 N€tgCfzO7 KzCOs Lumnite Graphite Methocement
cel
30.0
29.5
28. 9
29. 7
9.0
8.8
8. 7
8. 9
9.0
8.8
8. 7
8. 9
9.0
8.8
8. 7
8. 9
3.9
3.8
3. 7
3.9
29. 7
29. 7
29. 7
29. 3
29. 7
29. 3
8. 9
8. 9
8. 9
3. 9
5. 1
8. 9
8.8
8. 9
8. 8
8.9
8. 8
3. 9
3. 8
5.0
5.9
V0504
21110
V205
NILVO;
5.1
5.0
4. 9
5.0
0
.5
1. 0
. 25
,5
.5
1. 9
Feed rate, grits/hr.
Gasi?cation
Operating
Run No.
‘
temp.,
° C.
As V
Percent
styrene
11.13.
615
615
605
615
605
620
620
6
0.5
1. 0
0.25
0. 5
0.5
1. 0
Percent
Percent
conv.1 to
styrene
yield 1 of
styrene
‘
E10
32. 9
31. 6
32. 4
32. 2
31. 0
32. 3
32. 5
AS V
65. 9
61. 9
61. 4
62. 4
61.2
63. 7
61. 8
41.0
40. 8
40. 7
41. 3
40. 8
40. 0
40. 6
40.96
40.98
40. 86
41. 42
20. 91
40. 13
40. 78
90. 58
94.19
93. 12
92.60
93. 25
92. 44
93. 36
Ft?/lb.
Fti/lb.
E33. ted
styrene
made
2. 469
1. 951
2.010
2. 163
2.063
2.080
1. 999
6.027
4. 760
4. 918
5. 221
5.042
5. 183
4. 902
1. Calculated on vent gas measurement and analysis.
products.
Gaseous products were analyzed by mass spec- 45
trometric methods. The conversion and yield values were
calculated via a total carbon~hydrogen balance incorporat
ing both the liquid‘ and gas phases.
EXAMPLE 2
The procedure of Example 1 was repeated with the
catalysts and results as given in following Table II.
Table II
SELF-REACTIVATING STYRENE CATALYSTS
Catalyst composition, weight percent
Run N0.
mo,
ZnO
'
~
'
C1110 N€11CrzO7 K100i
Lnrnnite Graphite Methoeel MgO
'
CrzOs
VOSO-t-
cement
V205
7.60
0
0
0. 5
0
0. 5
6
0.5
5.0
1. 5
2. 5
Operating
temp, ° C.
655
650.
625
625
600
625
650
610
615
.10
. 50
7.00
0
6. 95
7. 00
0
. 10
.10
. 50
.10
. 10
8. 86
. 50
. 10
8. 20
8. 90
8. 50
5.00
1. 50
2. 50
Feed rate, gms./hr.
As V
Tannic
acid
6. 95
Run No.
As V
.2Hn0
EB.
33. 1
32. 4
31. 9
33. 0
32. 1
31. 2
32.15
32. 2
32. 5
‘
1120
64. 1
62. 5
61.8
62. 2
61. 9
58. 7
62.1
62. 5
60.7
Gasi?cation
Percent
styrene
Percent eonv.
to styrene
Percent yield
of styrene
Ft?/lb.
E.B. ted
40. 0
40. 0
40. 3
40. 1
40. 1
40. 1
38.9
40. 1
40.5
40. 00
40. 06
40.05
39. 94
39. 75
39. 83
38. 31
40.29
40.62
88.05
90. 25
90. 00
90. 65
85. 21
89. 69
85.44
93. 22
91. 67
2. 264
2. 088
2. 912
2. 673
2. 951
2. 908
3. 502
2. 140
2. 227
FtJ/lb.
styrene made
5. 660
5. 212
7. 280
6.683
7. 425
7. 299
9. 140
5.311
5. 483
3,084,125
5
6
The results obtained with the catalysts of Examples 1
What is claimed is:
and 2 are given in the accompanying drawing wherein
A catalyst consisting of 29.7 weight percent FezOs,
percent vanadium in the catalyst is plotted against percent
29.7 percent ZnO, 8.9 percent of each of CuzO, Na2Cr2O7,
yield of styrene and against gasi?cation, ft. 3/lb. styrene.
and K2CO3, 5.1 percent graphite, 3.9‘ percent of a refrac
The graphic results are summarized in the following table. 5 tory cement, 4 percent of a methyl cellulose having a
viscosity as a 2 percent solution in water of 2000 to 3000
Table III
Percent vanadium in
catalyst
Percent yield
of styrene
centipoises and 0.9 percent V205, which catalyst is self
Gasi?cation,
It. 3/11). styrene
0. O0
0. 25
0. 50
1.00
1. 50
2. 50
90. 58
92. 60
93. 59
93. 24
93. 22
91. 67
6.027
5. 221
4. 904
4, 910
5. 311
5. 483
5.00
85. 44
9. 140
reactivating in the presence of steam at 550° to 675° C.
References Cited in the ?le of this patent
10
UNITED STATES PATENTS
1,986,241
2,385,4842,457,719
2,481,824
2,615,899
2,666,086
2,824,074
2,870,228
Wul?” et al. ____________ __ Jan. 1,
Wright ______________ __ Sept. 25,
Pine et al _____________ __ Dec. 28,
Claussen et al _________ __ Sept. 13,
Sears ________________ __ Oct. 28,
1935
1945
1948
1949
1952
Pitzer ________________ __ Jan. 12, 1954
Sieg _________________ __ Feb. 18, 1958
Armstrong et al ________ __ Jan. 20, 1959
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